Liquid fuel cooking stove

ABSTRACT

A portable liquid fuel stove is disclosed herein which is particularly suited for cooking out of doors. The stove includes an annular shaped, cast fuel tank with a central opening having circumferentially spaced depending bottom ribs and upstanding top ribs both preferably cast with the fuel tank to form an integral unit. A control valve assembly preferably extends radially inwardly from the tank, and a fuel vaporizing section extends transverse to the valve assembly in axial alignment within the central opening in a lower portion of the tank. Vaporized fuel is passed from the fuel vaporizing section through an orifice disposed within the central opening in a lower portion of the tank to provide a stream of vaporized fuel. A burner cup in the central opening is substantially confined within the vertical extent of the tank to provide a mixing chamber. The flame produced heats the tank to pressurize the tank to force the fuel from the tank into the vaporizing chamber and vaporize the fuel in the vaporizing chamber for continuous burning.

United States Patent White, Jr. et al.

Nov. 21, 1972 [54] LIQUID FUEL COOKING STOVE [72] Inventors: Michael W.White, Jr.; Jacques A.

Plamondon, both of Denver, Colo.v

[73] Assignee: Colorado Technologists Incorporated, Englewood, C010.

[22] Filed: July 8, 1971 [21] Appl. No.: 160,747

[52] U.S. Cl ..126/44, 431/243 [51] Int. Cl. ..F24c 5/02 [58] Field ofSearch ...126/44, 38; 431/243, 247, 242

[56] References Cited UNITED STATES PATENTS 694,173 2/1902 Neivbold..126/38 2,444,444 7/1948 Howard ..126/44 2,498,682 2/1950 Howard..126/38 2,928,386 3/1960 Keyt et al. ..126/44 Primary Examiner-Charles.l. Myhre Assistant ExaminerHarold Joyce Att0rneyReilly & Lewis ll'C o IVF -43 6 9 5 M 37 [57] ABSTRACT A portable liquid fuel stove isdisclosed herein which is particularly suited for cooking out of doors.The stove includes an annular shaped, cast fuel tank with a centralopening having circumferentially spaced depending bottom ribs andupstanding top ribs both preferably cast with the fuel tank to form anintegral unit. A control valve assembly preferably extends radiallyinwardly from the tank, and a fuel vaporizing section extends transverseto the valve assembly in axial alignment within the central opening in alower portion of the tank. Vaporized fuel is passed from the fuelvaporizing section through an orifice disposed within the centralopening in a lower portion of the tank to provide a stream of vaporized.fuel. A burner cup in the central opening is substantially confinedwithin the vertical extent of the tank to provide a mixing chamber. Theflame produced heats the tank to pressurize the tank to force the fuelfrom the tank into the vaporizing chamber and vaporize the fuel in thevaporizing chamber for continuous burning.

23 Claims, 4 Drawing Figures PATENTED NOV 2 1 m2 vN R0 w 5 0 R WM 0 T HMT WP M A WA as YU HQ mm. MJ B 4 LEQUID FUEL COOKING STOVE This inventionrelates to an improved stove fueled by a liquid fuel which becomesvaporized by the heat generated by the stove and develops its owninternal pressure for producing continuous burning.

Some attempts have been made to provide self-pressurizing stovessuitable for cooking out of doors on camping trips and in the military.Certain difficulties attendant to such stoves include general complexityof construction, a difficulty in providing a rapid start, a lack ofeffective fuel vaporization and in providing sufficient tank pressuresto sustain continuous burning whereby in some cases an auxiliary pump isrequired to force the fuel into the burner. The present invention isintended to afford many advantages and improvements over previouslyknown pressurized liquid fuel cooking stoves.

Accordingly, it is a general object of this invention to provide animproved liquid fuel stove capable of generating its own internalpressure for continuous burning, capable of effectively vaporizing theliquid fuel and capable of effectively shielding the flame against beingput out by the wind or the like, particularly during starting.

Yet another object of this invention is to provide an improved cookingstove apparatus which is principally characterized by a simple, durableconstruction with a minimum number of parts which are relativelyinexpensive to manufacture and assemble and has improved heat transfercharacteristics making it highly effective in producing its own tankpressure and in vaporizing the liquid fuel for the burning thereof.

In accordance with the present invention, a preferred form has a hollow,generally annular cast fuel tank with a central opening havingcircumferentially spaced top upstanding ribs to support a cookingutensil above the fuel tank and having depending circumferentiallyspaced bottom ribsto support the tank above a supporting surface forefiective air circulation, the ribs being made integral with the tank. Acontrol valve assembly extends radially fromthe tank and a vapor sectionextends transversely thereto and passes vaporized fuel through anorifice to produce a stream of vaporized fuel. A generally conicalburner cup surrounds and extends upwardly from the orifice to define amixing chamber, the cup being substantially confined within the verticalextent of the tank by having a major portion thereof located within thevertical extent of the central opening of the tank to shield the flameand provide good heat transfer to and from the tank whereby a stream ofthe vaporized fuel passes through the orifice and mixes with air in theburner cup and is deflected through annular spaces at the top of the cupto produce a flame which is characterized by a relatively evendistribution.

Other objects, advantages and capabilities of the present invention willbe more readily appreciated and understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a top plan view of a cooking stove embodying features of thepresent invention;

FIG. 2 is a bottom plan view of the cooking stove shown in FIG. 1;

FIG. 3 is a side elevation view of the stove shown in FIGS. 1 and 2drawn approximately to scale; and

FIG. 4 is a vertical sectional view taken along lines 4-4 of FIG. 1 andthe same side as FIG. 3.

Referring now the the drawings there is shown an annular ortoroidal-shaped fuel tank 11 having a bottom wall 11a, top wall 11b andspaced inner and outer side walls and 11d, respectively, the corners ofthe tank being rounded and the inner side walls forming an axiallyextending central opening generally designated by numeral 12. The fueltank has top ribs 13 extending upwardly from the top wall thereof andarranged at circumferentially spaced intervals along the top wall, theribs terminating in flat top edges all of which are in the same plane tosupport a cooking utensil such as a skillet above the fuel tank. Thefuel tank 11 also has a plurality of depending bottom ribs 14 extendingdown from the tank and arranged at circumferentially spaced intervalsalong the bottom wall to provide legs. The legs terminate in the sameplane to support the fuel tank above a support surface permitting air toflow upwardly into the center of the tank to support combustion.

The fuel tank 11 has an inwardly directed feed tube projection orprojecting part 15 provided with a radially extending internallythreaded bore 16 opening into an inner sump portion 7, the sump portionbeing of relatively narrow width as compared to the full circumferentialextent of the fuel tank. The sump portion 17 is located in a lowerposition than the bottom wall 11a of the tank so that the last remainingpart of the fuel will pass from the tank. The fuel tank 11, upper andlower ribs 13 and 14, and projecting portions 15 preferably are made asan integral one-piece unit by casting in a single casting mold fromaluminum or a like material which makes a unit which is lightweight,extremely durable, relatively inexpensive to manufacture and capable ofwithstanding the required relatively high pressures.

In order to fill the fuel tank, a portion of the outer side wall 11d ofthe tank is formed with an annular inturned flange or filler neck 18with internal threads to provide an inlet opening 19 formed therein. Thefiller neck 18 defines an annular expansion space or void 18a between itand the walls of the tank. A removable plug or filler cap 20 with aknurled head portion 20a and an externally threaded body portion 20bthreads into the threaded flange 18 to close the fuel opening 19. Thefiller cap 20 is made hollow or bored out to form another expansion void21 in the fuel tank. These expansion voids 18a and 21 prevent expansionof fuel (due to a rapid change in temperature) from bursting the tankwalls. An O-ring type seal 22 is supported in a groove in the headportion 20a which bears against a recessed surface in the outer sidewall of the tank to form a seal so as to prevent loss of pressure in thetank. A generally C-shaped ring 25 is mounted on the plug 20 and hasintumed end portions inserted into openings in the head portion 20a tofacilitate the carriage of the tank on a belt and provide added leveragefor tightening and loosening the plug. The fuel tank may be initiallyfilled through opening 19 by a suitable liquid fuel represented at 26.The fuel may be a variety of types such as kerosene, gasoline or thelike which will vaporize rapidly when heated.

A control valve assembly for regulating the fuel flow from the fuel tank11 includes a valve housing or valve body 31 having oppositely disposedend portions 32 and 33. End portion 32 is provided with external threadsand is threaded into projecting part to secure the valve body to thetank. End portion 33 has internal threads. The valve body 33 has alongitudinal bore 34 extending throughout its lengthwise extent throughwhich an elongated metering rod or needle valve stem 37 extends. Thevalve stem 37 had an externally threaded portion 38 which threads intointernal threads 39 formed in the longitudinal bore 34 of the valvebody. The valve stem has a gradually tapering end portion 41 which isadapted to engage a tapered complementary shaped valve seat 42 formedalong the horizontal bore 34. The tapered end portion 41 and the valveseat 42 is quite gradual or only slightly tapered to provide very closemetering or fuel regulation.

The valve stem terminates at its free central end in a knob 43 which isturned by the user to open and close the control valve assembly. A cap44 with a head portion 44a and external threads is threaded into thethreaded end portion 33 and a gas seal 45 is provided inside the valvebody and around the stem to prevent gas leakage along the stem. The gasseal 45 is shown to comprise a pair of rings sandwiched between a pairof washers, all of which encompass the stem rearwardly of the threadedportion 38. The threading of the stem through the valve body serves toopen and close the flow passage thereof and the valve body closelyregulates the flow of fuel from the tank through the valve body.

A vaporizing chamber 49 is formed in flow communication with thehorizontal bore by providing a vertically disposed bore 46 with internalthreads extending through the top of the valve body 31 and thenextending into the longitudinal bore 34. A hollow nozzle member 48having a hexagonal head portion 48a and an externally threaded part 48bwith an internal bore threads into the internal threads in the verticalbore 46 to define a vaporizing section forming the vaporizing chamber49. The stem 37 has a recessed portion 37a which is beveled at the endsand cooperates with the lower end of threaded part 48a extending intothe longitudinal bore to prevent the stem from being removed and/oropening of the valve causing an excessively high flame. A narrowrestricted orifice 51 is formed in the head portion 48a to discharge thevaporized fuel in a fine spray or jet as it passes from the vaporchamber. The internal bore of the nozzle member 48 has a main boreportion of uniform cross-section and an upwardly tapered bore portion 52leading into the restricted orifice 51. A free-rolling ball valve 53 iscarried in the bore of the nozzle member 48 and engages the taperedsurface 52 which acts as a valve seat therefor to prevent the loss offuel when the tank is placed in an inverted position. The nozzle member48 has a tapered portion 48c which is complementary to a chamfer in thevertical bore forcing the bottom of the burner cup 55 to form a chamfer.

As best seen in FIG. 4, the nozzle member 48 and orifice 51 are locatedwithin the center of the tank and at a point substantially below themidpoint of the tank along a vertical line through the axis of the fueltank and is preferably approximately at the fuel level of the bottom ofthe tank. This allows the fuel to flow by gravity feed from the tankinto the vapor chamber for the starting of the stove and also locatesthe nozzle member and vapor chamber relative to the tank so that theywill receive a substantial amount of heat from the tank.

A vapor-air mixing assembly located above the nozzle member 48 andwithin the center of the tank of the stove comprises a burner cup 55having an inverted bell shape or conical shape with an upwardlydivergent side wall portion 550 and an inturned base portion 55bprovided with a central opening therein. The side wall portions 55a haveopenings 56 to admit primary air into the mixing chamber 57 formed bythe cup for mixing with the fuel vapor emitting from the nozzle withprimary air coming in through the side openings 56. The burner cup issubstantially confined within the vertical extent of the tank in that amajor portion of the cup is located within the vertical extent of thetank. This provides a substantial shielding of the flame and affordsgood heat transfer between the tank and'cup.

A flame deflector plat 58 extends across the top of the burner cup 55with the deflector plate being of a concave-convex shape having aplurality of circumferentially spaced outwardly extending relatively narrow tabs 59 which are bent to releasably engage the upper edge of thecup and leave annular spaces 61 between the tabs through which a mixtureof fuel vapor and air pass to produce a flame above the deflector plateduring the operation thereof. The annular spaces 61 and location of thetop of the cup afford a burner flame more closely resembling that of thegas range, with a more even flame and heat distribution, and anessentially blue flame is produced. The nozzle member 48 extends throughthe opening in the base portion 55b and threads into the vertical baseof the valve body and the head portion 48a engages the upper surface ofthe base portion so as to releasably secure the burner cup 55 in placeon top of the valve body with the threading of the nozzle member intothe bore 46 forming a chamfer in the bottom of the cup, as best seen inFIG. 4.

In the entire sequence of operation for the abovedescribed stove, thecontrol valve is initially opened only slightly to permit a relativelysmall quantity of fuel to pass by gravity feed or flow into the vaporchamber 49 and up through the nozzle orifice 51. The valve is thenclosed and the fuel is lit either by introducing a match into the mixingchamber 57 through the side opening or actuating a suitable sparkgenerator device located in the mixing chamber or adjacent thereto. Thisproduces an initial flame in the mixing chamber 57 which in turn burns aportion of the fuel in the vapor chamber and the fuel in the vaporchamber is heated and begins to vaporize so that after a period offifteen to thirty seconds of burning in the mixing chamber the fuelbegins to vaporize within the vapor chamber causing a hissing effect.The control valve assembly is then opened slightly and the fuelcontinues to vaporize in the vapor chamber as a result of its beingheated up by the flame.

The fuel tank which begins to become heated by flame has vaporized fuelpassing through the orifice which mixes with primary air in the mixingchamber to produce a flame which gradually begins to extend through thetop openings 61. After initial heating, the flame moves from inside themixing chamber to above the mixing chamber where it combines withsecondary air above the deflector plate and provides a substantial flameabove the deflector plate. The deflector plate serves to spread theflame out through the top openings where it is in close proximity to andimpinges on the fuel tank to heat the fuel tank. As the flame burns apressure begins to build up in the fuel tank which tends to force thefuel from the tank past the control valve assembly and into the vaporchamber with the vaporized fuel being forced up through the orifice 51in a continuous feeding of the liquid fuel into the vaporizing chamberunder pressure provided in the tank.

During the lighting operation the flame stays inside the mixing chamber57 until proper draft occurs and it has been found that the flame isvery difficult to blow out. This point is important as to the overalloperation because many camper, hiker, fisherman and hunter finds himselfin a windy unprotected area, and to build even a small wood fire becomesdifficult due to the wind. This stove allows one to light it in winds ofa substantial velocity such as up to 30 mph and it will stay lit becauseof the flame being protected from the wind during the generation period.

It is therefore to be understood that various modifications and changesmay be made in the detailed construction and arrangement of partscomprising the preferred form of the present invention without departingfrom the spirit and scope thereof.

What is claimed is:

1. Cooking stove apparatus comprising:

a generally annular fuel tank with a central opening,

control valve means for regulating the flow of fuel from the tank havinga fuel vaporizing section at a discharge end thereof located within thecentral opening at the bottom of said tank,

a nozzle disposed within the central opening at the bottom of the tankhaving an orifice for discharging vaporized fuel passing from said fuelvaporizing section in a fine stream, and

means defining a mixing chamber disposed within said central opening andsubstantially confined within the vertical extent of said tank, saidmixing chamber mixing air with the stream of vaporized fuel passingthrough said orifice to produce a flame whereby heat produced by theflame heats the tank to pressurize the tank and vaporize fuel in thefuel vaporizing section.

2. Cooking stove apparatus as set forth in claim 1 wherein said nozzleorifice is located at approximately the level of the bottom of the tankwhereby the fuel may drain by gravity flow from the tank through saidorifice.

3. Cooking stove apparatus as set forth in claim 1 wherein said mixingchamber is defined by a generally conical cup-shaped burner member madeof a heatconductive material having walls in close proximity to theinner walls of said tank to transfer heat produced by the flame to saidtank.

4. Cooking stove apparatus as set forth in claim 3 wherein saidcup-shaped burner member diverges upwardly and terminates in a topopening slightly above the top wall of the fuel tank and a flamedeflector partially covering said top opening and forming therewithannular openings along the outer periphery of the cupshaped burnermember for the discharge of a vaporized fuel and air mixture to producea flame.

5. Cooking stove apparatus as set forth in claim 4 wherein saidcup-shaped burner member has openings in the side thereof to admitprimary air into the mixing chamber.

6. Cooking stove apparatus as set forth in claim 1 wherein said fueltank has depending ribs at circumferentially spaced intervals along thebottom thereof to support the tank above a support member and upstandingribs at circumferentially spaced intervals along the top of the tank tosupport a cooking utensil above the top of the tank.

7. Cooking stove apparatus as set forth in claim 6 wherein said tank andbottom and top ribs are cast as an integral unit.

8. Cooking stove apparatus as set forth in claim 1 wherein said controlvalve means includes a valve body mounted along an inner side wall ofthe tank which extends radially inwardly thereof, said valve body havinga longitudinal bore provided with a tapered valve seat in flowcommunication with the inside of the tank and a valve stem having atapered portion adapted to move through said bore to meter the fuel flowfrom said tank into said vaporizing section.

9. Cooking stove apparatus as set forth in claim 8 including a recess inthe stern cooperating with said nozzle to limit the movement of the stemin the valve body.

10. Cooking stove apparatus as set forth in claim 8 wherein said valvebody has an upper portion formed with a vertical bore opening into saidlongitudinal bore, said nozzle being fitted in said vertical bore forforming said fuel vaporizing section.

11. Cooking stove apparatus as set forth in claim 1 wherein said nozzlecontains a movable valve member adapted to close the orifice when thenozzle is inverted.

12. Cooking stove apparatus as set forth in claim 11 wherein saidmovable valve member is in the form of a ball.

13. Cooking stove apparatus as set forth in claim 1, said fuel tankhaving means defining an expansion void for the fuel.

14. Cooking stove apparatus as set forth in claim 12 wherein said meansdefining an expansion void includes a radially extending filler neckflange formed in a side wall of the tank leaving a space between thefiller neck flange and the inner walls of thetank.

15. Cooking stove apparatus as set forth in claim 12 wherein said meansdefining an expansion void includes a removable plug in the tank havinga hollow portion in the plug.

16. Cooking stove apparatus comprising:

a generally toroidal-shaped fuel tank with a central opening,

control valve means for regulating the flow of fuel from the tank havinga fuel vaporizing section at a discharge end thereof located within thecentral opening of said tank,

a nozzle disposed within the central opening having an orifice fordischarging vaporized fuel passing from said fuel vaporizing section ina fine stream, said orifice being located below the midpoint of thevertical extent of the tank so that fuel may flow by gravity feed intosaid orifice, and

means defining a mixing chamber within said central opening andsurrounded by said tank for mixing air with the stream of vaporized fuelpassing through said orifice to produce a flame whereby heat produced bythe flame heats the tank to pressurize the tank and vaporize fuel in thefuel vaporizing section.

17. Cooking stove apparatus comprising a generally annular fuel tankwith a central opening, control valve means extending radially inwardlyfrom the tank for regulating the flow of fuel from the tank, said valvemeans having a fuel vaporizing section in flow communication therewith,a nozzle member in flow communication with the vaporizing section havingan orifice for discharging the vaporized fuel in a fine stream, saidorifice being located at least below the midpoint of the vertical extentof the tank so that fuel may flow by a gravity feed into said orifice,and a burner cup extending upwardly from the nozzle member defining amixing chamber for mixing air with the fine stream of vaporized fuel toproduce a flame, said burner cup being substantially confined within thetank with a major portion of the burner cup being located within thevertical extent of said tank whereby heat produced from the flameproduces a pressure in the tank to force the fuel into the vaporizingchamber and heat from the tank transmitted to the vaporizing sectionvaporizes the fuel in the vaporizing chamber.

18. Portable self-pressurizing cooking stove apparatus comprising:

a toroidal-shaped integrally cast fuel tank with a central opening madeof a heat conductive material, said fuel tank having a removable plug insealed engagement with a wall portion thereof for the filling of thetank with fuel, a hollow, radially inwardly extending projecting portionforming a fuel feed line connector from the tank and having a sumpportion opening into the projecting portion, and a flanged neck portiondefining a fill opening into the tank, said neck portion being spacedfrom the inner walls of the tank to form a fuel expansion void, saidfuel tank having depending ribs at circumferentially spaced intervalsalong the bottom of the tank to support said tank above a supportsurface and upstanding top ribs at circumferentially spaced intervalsalong the top of the tank to support a cooking utensil above said tank,said bottom and top ribs being cast integral with said tank,

a control valve assembly including a valve body with a longitudinal borereleasably secured to aid projecting portion and extending radiallyinwardly from said tank, said horizontal bore having a tapered valveseat portion, aneedle-type valve stem extending through saidlongitudinal bore having a tapered portion movable axially along saidvalve seat to meter fuel flow from the fuel tank, said valve body havingan upright transverse bore opening into said longitudinal bore,

a hollow nozzle member threaded into said upright bore to form avaporizing chamber for vaporizing fuel metered past said valve stem,said nozzle member having a restricted orifice for discharge of thevaporized fuel in a jet stream, said orifice being located atapproximately the bottom of the tank so that fuel will flow by the forceof gravity through said orifice, said nozzle member projecting into saidupright bore and into engagement with a beveled recess in said valvestem to limit the movement of the valve stem,

mixer assembly including a generally conical burner cap defining amixing chamber surrounding and extending upwardly from said nozzleorifice within the central opening of the fuel tank, a major portion ofthe burner cap being located within the vertical extent of the tank,said burner cap having side openings to admit primary air into saidmixing chamber and having a deflector plate across the top thereof todeflect the flame through annular top openings along the outer edges ofthe burner cup, said nozzle member being in engagement with the bottomof the burner cup to secure the cup to the valve body and transfer heatto the vaporizing chamber whereby heat produced by the flame heats thetank to pressurize the tank and vaporize the fuel in the vaporizingchamber.

19. Portable self-pressurizing cooking stove apparatus as set forth inclaim 18 wherein said nozzle member has a beveled edge adapted to bereceived by an inclined depression at the top of said upright bore toincline the bottom of the burner cup at an angle in its engagement withthe burner cup and the valve body.

20. In a self-pressurizing stove, the combination comprising:

a generally annular shaped cast fuel tank with a central opening, saidtank including spaced inner and outer side walls, a top wall and abottom wall arranged to form an inner fuel chamber, said tank having anopening into the fuel chamber formed in the outer wall with a removableplug in said opening, a flanged portion extending inwardly from an innersurface of said outer wall at said opening to form a fuel expansionvoid, and a projecting portion extending inwardly from the inner wallhaving a bore in communication with said fuel chamber, said tank havingdepending rib portions at circumferentially spaced intervals along thebottom wall to support said tank and upstanding top ribs atcircumferentially spaced intervals'along the top wall of the tank, saidflanged portion, projecting portion, depending ribs and upstanding ribsbeing cast integral with said tank, and

a valve and burner assembly mounted on said tank, said assemblyincluding a valve body connected to said projecting portion andextending radially inwardly therefrom having a bore in communicationwith the fuel chamber and a valve stem movable through the bore toregulate the flow of fuel therethrough, and a burner mounted on saidvalve body extending generally transverse thereto and coaxially arrangedin said central opening of said tank.

21. In a self-pressurizing stove is set forth in claim 20 wherein saidvalve body has external threads which thread into internal threads insaid projecting portion.

22. In a self-pressurizing stove, the combination comprising:

a generally annular fuel tank having a vertical axis and walls defininga central opening and an inner fuel chamber, and

means defining a fuel discharge orifice in said central opening at thebottom of the tank and a vapor chamber below and in flow communicationwith said fuel discharge orifice, said vapor chamber being in flowcommunication with said fuel chamber, said means including a valve bodywith a bore and valve stem, said valve body supported by an inner wallof said tank and extending radially inwardly therefrom, said valve stembeing movable in the bore to regulate the fuel flow from the fuelchamber through said vapor chamber and out said fuel discharge orifice.

1. Cooking stove apparatus comprising: a generally annular fuel tankwith a central opening, control valve means for regulating the flow offuel from the tank having a fuel vaporizing section at a discharge endthereof located within the central opening at the bottom of said tank, anozzle disposed within the central opening at the bottom of the tankhaving an orifice for discharging vaporized fuel passing from said fuelvaporizing section in a fine stream, and means defining a mixing chamberdisposed within said central opening and substantially confined withinthe vertical extent of said tank, said mixing chamber mixing air withthe stream of vaporized fuel passing through said orifice to produce aflame whereby heat produced by the flame heats the tank to pressurizethe tank and vaporize fuel in the fuel vaporizing section.
 1. Cookingstove apparatus comprising: a generally annular fuel tank with a centralopening, control valve means for regulating the flow of fuel from thetank having a fuel vaporizing section at a discharge end thereof locatedwithin the central opening at the bottom of said tank, a nozzle disposedwithin the central opening at the bottom of the tank having an orificefor discharging vaporized fuel passing from said fuel vaporizing sectionin a fine stream, and means defining a mixing chamber disposed withinsaid central opening and substantially confined within the verticalextent of said tank, said mixing chamber mixing air with the stream ofvaporized fuel passing through said orifice to produce a flame wherebyheat produced by the flame heats the tank to pressurize the tank andvaporize fuel in the fuel vaporizing section.
 2. Cooking stove apparatusas set forth in claim 1 wherein said nozzle orifice is located atapproximately the level of the bottom of the tank whereby the fuel maydrain by gravity flow from the tank through said orifice.
 3. Cookingstove apparatus as set forth in claim 1 wherein said mixing chamber isdefined by a generally conical cup-shaped burner member made of aheat-conductive material having walls in close proximity to the innerwalls of said tank to transfer heat produced by the flame to said tank.4. Cooking stove apparatus as set forth in claim 3 wherein saidcup-shaped burner member diverges upwardly and terminates in a topopening slightly above the top wall of the fuel tank and a flamedeflector partially covering said top opening and forming therewithannular openings along the outer periphery of the cup-shaped burnermember for the discharge of a vaporized fuel and air mixture to producea flame.
 5. Cooking stove apparatus as set forth in claim 4 wherein saidcup-shaped burner member has openings in the side thereof to admitprimary air into the mixing chamber.
 6. Cooking stove apparatus as setforth in claim 1 wherein said fuel tank has depending ribs atcircumferentially spaced intervals along the bottom thereof to supportthe tank above a support member and upstanding ribs at circumferentiallyspaced intervals along the top of the tank to support a cooking utensilabove the top of the tank.
 7. Cooking stove apparatus as set forth inclaim 6 wherein said tank and bottom and top ribs are cast as anintegral unit.
 8. Cooking stove apparatus as set forth in claim 1wherein said control valve means includes a valve body mounted along aninner side wall of the tank which extends radially inwardly thereof,said valve body having a longitudinal bore provided with a tapered valveseat in flow communication with the inside of the tank and a valve stemhaving a tapered portion adapted to move through said bore to meter thefuel flow from said tank into said vaporizing section.
 9. Cooking stoveapparatus as set forth in claim 8 including a recess in the stemcooperating with said nozzle to limit the movement of the stem in thevalve body.
 10. Cooking stove apparatus as set forth in claim 8 whereinsaid valve body has an upper portion formed with a vertical bore openinginto said longitudinal bore, said nozzle being fitted in said verticalbore for forming said fuel vaporizing section.
 11. Cooking stoveapparatus as set forth in claim 1 wherEin said nozzle contains a movablevalve member adapted to close the orifice when the nozzle is inverted.12. Cooking stove apparatus as set forth in claim 11 wherein saidmovable valve member is in the form of a ball.
 13. Cooking stoveapparatus as set forth in claim 1, said fuel tank having means definingan expansion void for the fuel.
 14. Cooking stove apparatus as set forthin claim 12 wherein said means defining an expansion void includes aradially extending filler neck flange formed in a side wall of the tankleaving a space between the filler neck flange and the inner walls ofthe tank.
 15. Cooking stove apparatus as set forth in claim 12 whereinsaid means defining an expansion void includes a removable plug in thetank having a hollow portion in the plug.
 16. Cooking stove apparatuscomprising: a generally toroidal-shaped fuel tank with a centralopening, control valve means for regulating the flow of fuel from thetank having a fuel vaporizing section at a discharge end thereof locatedwithin the central opening of said tank, a nozzle disposed within thecentral opening having an orifice for discharging vaporized fuel passingfrom said fuel vaporizing section in a fine stream, said orifice beinglocated below the midpoint of the vertical extent of the tank so thatfuel may flow by gravity feed into said orifice, and means defining amixing chamber within said central opening and surrounded by said tankfor mixing air with the stream of vaporized fuel passing through saidorifice to produce a flame whereby heat produced by the flame heats thetank to pressurize the tank and vaporize fuel in the fuel vaporizingsection.
 17. Cooking stove apparatus comprising a generally annular fueltank with a central opening, control valve means extending radiallyinwardly from the tank for regulating the flow of fuel from the tank,said valve means having a fuel vaporizing section in flow communicationtherewith, a nozzle member in flow communication with the vaporizingsection having an orifice for discharging the vaporized fuel in a finestream, said orifice being located at least below the midpoint of thevertical extent of the tank so that fuel may flow by a gravity feed intosaid orifice, and a burner cup extending upwardly from the nozzle memberdefining a mixing chamber for mixing air with the fine stream ofvaporized fuel to produce a flame, said burner cup being substantiallyconfined within the tank with a major portion of the burner cup beinglocated within the vertical extent of said tank whereby heat producedfrom the flame produces a pressure in the tank to force the fuel intothe vaporizing chamber and heat from the tank transmitted to thevaporizing section vaporizes the fuel in the vaporizing chamber. 18.Portable self-pressurizing cooking stove apparatus comprising: atoroidal-shaped integrally cast fuel tank with a central opening made ofa heat conductive material, said fuel tank having a removable plug insealed engagement with a wall portion thereof for the filling of thetank with fuel, a hollow, radially inwardly extending projecting portionforming a fuel feed line connector from the tank and having a sumpportion opening into the projecting portion, and a flanged neck portiondefining a fill opening into the tank, said neck portion being spacedfrom the inner walls of the tank to form a fuel expansion void, saidfuel tank having depending ribs at circumferentially spaced intervalsalong the bottom of the tank to support said tank above a supportsurface and upstanding top ribs at circumferentially spaced intervalsalong the top of the tank to support a cooking utensil above said tank,said bottom and top ribs being cast integral with said tank, a controlvalve assembly including a valve body with a longitudinal borereleasably secured to aid projecting portion and extending radiallyinwardly from said tank, said horizontal bore having a tapered valveseat portion, a needle-type valve stem extending throUgh saidlongitudinal bore having a tapered portion movable axially along saidvalve seat to meter fuel flow from the fuel tank, said valve body havingan upright transverse bore opening into said longitudinal bore, a hollownozzle member threaded into said upright bore to form a vaporizingchamber for vaporizing fuel metered past said valve stem, said nozzlemember having a restricted orifice for discharge of the vaporized fuelin a jet stream, said orifice being located at approximately the bottomof the tank so that fuel will flow by the force of gravity through saidorifice, said nozzle member projecting into said upright bore and intoengagement with a beveled recess in said valve stem to limit themovement of the valve stem, a mixer assembly including a generallyconical burner cap defining a mixing chamber surrounding and extendingupwardly from said nozzle orifice within the central opening of the fueltank, a major portion of the burner cap being located within thevertical extent of the tank, said burner cap having side openings toadmit primary air into said mixing chamber and having a deflector plateacross the top thereof to deflect the flame through annular top openingsalong the outer edges of the burner cup, said nozzle member being inengagement with the bottom of the burner cup to secure the cup to thevalve body and transfer heat to the vaporizing chamber whereby heatproduced by the flame heats the tank to pressurize the tank and vaporizethe fuel in the vaporizing chamber.
 19. Portable self-pressurizingcooking stove apparatus as set forth in claim 18 wherein said nozzlemember has a beveled edge adapted to be received by an inclineddepression at the top of said upright bore to incline the bottom of theburner cup at an angle in its engagement with the burner cup and thevalve body.
 20. In a self-pressurizing stove, the combinationcomprising: a generally annular shaped cast fuel tank with a centralopening, said tank including spaced inner and outer side walls, a topwall and a bottom wall arranged to form an inner fuel chamber, said tankhaving an opening into the fuel chamber formed in the outer wall with aremovable plug in said opening, a flanged portion extending inwardlyfrom an inner surface of said outer wall at said opening to form a fuelexpansion void, and a projecting portion extending inwardly from theinner wall having a bore in communication with said fuel chamber, saidtank having depending rib portions at circumferentially spaced intervalsalong the bottom wall to support said tank and upstanding top ribs atcircumferentially spaced intervals along the top wall of the tank, saidflanged portion, projecting portion, depending ribs and upstanding ribsbeing cast integral with said tank, and a valve and burner assemblymounted on said tank, said assembly including a valve body connected tosaid projecting portion and extending radially inwardly therefrom havinga bore in communication with the fuel chamber and a valve stem movablethrough the bore to regulate the flow of fuel therethrough, and a burnermounted on said valve body extending generally transverse thereto andcoaxially arranged in said central opening of said tank.
 21. In aself-pressurizing stove is set forth in claim 20 wherein said valve bodyhas external threads which thread into internal threads in saidprojecting portion.
 22. In a self-pressurizing stove, the combinationcomprising: a generally annular fuel tank having a vertical axis andwalls defining a central opening and an inner fuel chamber, and meansdefining a fuel discharge orifice in said central opening at the bottomof the tank and a vapor chamber below and in flow communication withsaid fuel discharge orifice, said vapor chamber being in flowcommunication with said fuel chamber, said means including a valve bodywith a bore and valve stem, said valve body supported by an inner wallof said tank and extending radially inwardly therefrom, said valve stembeing movablE in the bore to regulate the fuel flow from the fuelchamber through said vapor chamber and out said fuel discharge orifice.